Increased Thyroid Function Research Articles

CLINICAL FUNCTIONAL CHARACTERISTICS OF SICK CHILDREN WITH GLOMERULONEPHRITIS WITH INCREASED THYROID FUNCTION

Abstract: To date, there have been few works on a comprehensive study of the functional state of the thyroid gland in glomerulo- and pyelonephritis in children, but there is no consensus on the nature of these relationships (12,13,14). Purpose of the work: to study the clinical and functional characteristics of sick children with glomerulonephritis with increased thyroid function. Material and methods of research: The work is based on clinical observations, examination and treatment of 22 children with glomerulonephritis with hyperfunction of the thyroid gland aged 5 to 17 years, who were hospitalized in the neurological department. Conclusions: characterizing the features of the clinical course of glomerulonephritis in children with increased activity of the thyroid system, one should first of all note the presence of 2 clinical variants of the disease: acute glomerulonephritis with nephritic syndrome, which was characterized by an acute onset with symptoms of general intoxication, early appearance of renal symptoms, and the presence of mixed polymorphic urinary syndrome , pronounced edema, a variety of extrarenal changes.

Familial Dysalbuminemic Hyperthyroxinemia Induced by Mutation R218H of Albumin

Familial Dysalbuminemic Hyperthyroxinemia (FDH) is thought of no clinical significance, but tends to to misdiagnosed and mistreated as Graves’ hyperthyroidism with long time. In a Chinese family to explore clinical characteristics, hereditary features and gene variation of FDH and its effect on pregnancy. Methods: Two propostitus (a father and his son) with hyperthyroidism were re-diagnosed as FDH due to the canonical profile of measured thyroid hormones. After screening thyroid function of the whole family, eight affected of FDH were identified among total thirteen lineal relatives. They were studied in terms of clinical history, biochemical and hormone examination, thyroid imaging and TSH secreting test by dexamethasone and bromocriptine. Three members accepted gene analysis with the next generation sequencing followed by Sanger method. Productive history was investigated in five spouse of the whole family. Results: In the two propostitus, FDH exhibited very high total thyroxine (T4) and mild high total triiodinethyronine (T3), and normal free T4 and T3 besides normal thyroid stimulating hormone (TSH). In addition, ultrasound discovered diffuse goiter and enhanced blood flow, and 99mTc uptake increased, while TSH receptor antibody and pituitary MRI scan remained normal. Other six family members had similar changes of the thyroid hormones and normal TSH which could be suppressed dramatically by dexamethasone and bromocriptine, then were suspected of FDH and thereafter confirmed with gene analysis. Among these eight FDH, four were misdiagnosed with hyperthyroidism and mistakenly received anti-thyroid medication at least one year. Gene analysis of three members revealed R218H variation of albumin gene. Conclusions: R218H associated FDH shows canonical changes of thyroid hormones with increased thyroid function, high penetrance and misdiagnose rate with hyperthyroidism, it exerts no effect on pregnancy.

Posthemithyroidectomy Pregnancy Thyroid Function Surveillance: Frequency, Adherence, and Guideline Impact

ObjectivePosthemithyroidectomy women are at an increased risk for gestational subclinical hypothyroidism. Therefore, the American Thyroid Association (ATA) recommends increased thyroid function surveillance for this subgroup of pregnant women. The purpose of this study was to evaluate the frequency of thyroid function surveillance during pregnancy in posthemithyroidectomy women and to evaluate the adherence to the 2017 ATA guidelines and its possible impact since being published on thyroid function surveillance rates. MethodsA retrospective study of pregnant posthemithyroidectomy women operated at our institution between 1997 and 2020 was performed. The study cohort was subdivided by pregnancy dates before 2018 and 2018 onward to evaluate the impact of the 2017 ATA guidelines. Adherence to the guidelines was defined as at least 1 thyroid-stimulating hormone test in each trimester. ResultsAfter exclusions, a total of 120 pregnancies conceived by 66 women who underwent hemithyroidectomy surgeries were included in this study. Overall, serum thyroid-stimulating hormone examinations were performed during the first, second, and third pregnancy trimesters in 86.6%, 40%, and 16.6% of pregnancies, respectively (P <.005). The examination rate since 2018 was 88%, 40%, and 8% for the first, second, and third trimesters, respectively (P <.005). ConclusionAdherence to the latest ATA guidelines is low, and its publication in 2017 did not increase the thyroid function surveillance rate in posthemithyroidectomy women. Better patient education regarding the risks of gestational hypothyroidism following hemithyroidectomy and improved communications among treating surgeons, obstetricians, and endocrinologists may improve these rates.

Funkcionalni poremećaji štitaste žlezde u farmaceutskoj praksi - kako možemo pomoći našim pacijentima?

Functional thyroid disorders (hypothyroidism and hyperthyroidism) are amongst the most common endocrine disorders pharmacists encounter on a daily basis. They are highly prevalent in iodine-replete areas, and affect women about 10 times more often than man. Hypothyroidism (thyroid hormone deficiency) is usually caused by Hashimoto's thyroiditis, an autoimmune disorder that leads to gradual thyroid destruction. The drug-of-choice for treating hypothyroidism is levothyroxine, a synthetic form of thyroxine. Key points which need to be discussed with patients who are prescribed levothyroxine for the first time are when/how to administer this drug, how its effects are monitored, what drugs may affect its efficacy, and the importance of properly treating hypothyroidism during pregnancy. Hyperthyroidism (increased production of thyroid hormones) is most often caused by Graves' disease, another thyroid autoimmune disorder in which stimulatory autoantibodies against the TSH receptor lead to increased thyroid function. Graves' disease is most commonly treated with thionamide drugs (thiamazole, carbimazole or propylthiouracil) and patients using these drugs should be advised on the monitoring requirements, duration of treatment, and how to recognize possible serious adverse effects (agranulocytosis and hepatotoxicity), and informed that these drugs must be used during pregnancy in order to reduce the risk of adverse outcomes for the mother and baby.

515Association between hysterectomy and risk of thyroid cancer

Abstract Background Hysterectomy (surgical removal of the uterus) has been consistently associated with increased thyroid cancer risk. While there may be a biologic explanation, increased ascertainment (over-diagnosis) because of greater healthcare use by women having this procedure might also contribute to the observed increased risk. We explored this association considering indications for hysterectomy, age at hysterectomy, and the potential for the association to be mediated by increased contact with health professionals or increased thyroid function testing. Methods We recruited 730 women diagnosed with thyroid cancer and 785 age-matched population controls. We estimated odds ratios (OR) using logistic regression to assess the associations and used causal mediation analysis to investigate potential mediation. Results Prior hysterectomy was associated with an increased thyroid cancer risk (OR = 1.55, 95% CI: 1.14-2.12). When stratified by indication for hysterectomy, the increased risk was apparent only among those who had undergone hysterectomy for bleeding disorders (OR = 1.79, 95% CI: 1.26-2.56). Additionally, the association varied by age at hysterectomy (&amp;lt;55 years, OR = 1.68, 95% CI: 1.22-2.31 versus ≥ 55 years, OR = 0.87, 95% CI: 0.42-1.81). Around 30% of the association was mediated by more frequent use of healthcare services. Conclusions Hysterectomy for bleeding disorders was associated with an increased risk of thyroid cancer among women and a moderate proportion of this appeared due to frequent medical contact. Key messages The way in which women use health services probably explains at least some of the association between hysterectomy and risk of thyroid cancer.

Melatonin ameliorates ketoconazole-induced increase in thyroid function

Background&#x0D; The antithyroid effect of ketoconazole has been reported. The secretion and action of melatonin in the thyroid gland are also known. However, the possible effect of melatonin on ketoconazole-induced antithyroid effect is unknown.&#x0D; Objective&#x0D; We sought to investigate the modulatory effect of ketoconazole and/or melatonin on thyroid function in female rats.&#x0D; Methods&#x0D; Groups 1-4 of female rats respectively underwent 14-day treatment with normal saline, 25 mg/kg ketoconazole, 4 mg/kg melatonin and 10 mg/kg melatonin. Groups 5 and 6 both received 14-day treatment with ketoconazole and were respectively treated with 4 mg/kg melatonin and 10 mg/kg melatonin simultaneously. Groups 7 and 8 respectively underwent 14-day pretreatment with 4 mg/kg melatonin and 10 mg/kg melatonin, followed by 14-day administration of ketoconazole to both groups. Groups 9 and 10 were both treated with ketoconazole for 14 days, followed by respective 14-day administration of 4 mg/kg melatonin and 10 mg/kg melatonin.&#x0D; Results&#x0D; TSH, T3, T4, and iodine concentrations were increased by separate administration of ketoconazole and either dose of melatonin when compared to control. However, pre-treatment or post-treatment of ketoconazole-treated rats with melatonin abolished the ketoconazole-induced increase in TSH, T3, T4, and iodine while co-administration of ketoconazole with melatonin caused no improvement in the ketoconazole-induced increase in TSH, T3, and T4 except iodine concentration.&#x0D; Conclusion&#x0D; Ketoconazole increased thyroid function, which was ameliorated by pre- or post-treatment with melatonin, possibly via modulation of the iodination process.&#x0D; Keywords: Iodine; Ketoconazole; Melatonin; Thyroid function; Toxicity

The impact of nandrolone decanoate abuse on experimental animal model: Hormonal and biochemical assessment

Nandrolone decanoate (ND) is one of the most commonly abused anabolic androgenic steroids compounds in the world owing to its ability to improve physical performance but its abuse is associated with several adverse effects. The current study was performed to evaluate the effect of recommended and overdose of nandrolone decanoate (ND) for short and long term on the alterations of biochemical markers related to kidney, liver, adrenal, thyroid gland functions and oxidant and antioxidant activities. Sixty male rats were randomly assigned into two major groups. The first was treated with ND for 6 weeks and the second was treated with same drug for 12 weeks. Each of these groups was further subdivided into three sub groups: 1-Control (untreated rats), 2- Rats intraperitoneally injected with ND 3 mg/kg weekly, 3- Rats intraperitoneally injected with ND 15 mg/kg weekly. Administration of high ND dose for either short or long term significantly elevated kidney function biomarkers, liver enzymes both in serum, cytosol and mitochondria, insignificantly increased thyroid function, significantly increased adrenal function while, decreased ACTH. Moreover, oxidative stress biomarkers were significantly upregulated associated with depression in antioxidants activities. Administration of high ND dose for either short or long term as well as the repeated use of recommended ND dose for long term proved to have harmful effects manifested in impairing the functions of kidneys, liver, thyroid and adrenal glands as well as oxidant antioxidant balance.

Thyroid diseases: Pathophysiology and new hopes in treatment with medicinal plants and natural antioxidants

The thyroid gland regulates a wide range of physiological activities such as growth, metabolism, homeostasis, and cell proliferation and differentiation through the secretion of thyroid hormones (THs). Thyroid diseases are among the most common endocrine disorders, hypothyroidism is the most common clinical thyroid dysfunction. Hyperthyroidism means increased thyroid function and refers to excess metabolic state due to excessive synthesis and secretion of TH. Medicinal plants have been identified and used by humans throughout history. To name the herbs and natural antioxidants used to treat thyroid disorders including hypothyroidism and hyperthyroidism. Related articles were obtained using the Google Scholar, PubMed, and ScienceDirect databases. The results of this study indicate that medicinal plants include Fucus vesiculosus, Aegle marmelos, Coleus forskohlii, Linum usitatissimum, Withania somnifera, Commiphora mukul, Nigella sativa, and Bacopa monnieri. They can improve the hyperthyroidism in improving hyperthyroidism and herbal remedies, Melissa officinalis A. marmelos, Lycopus europaeus, Leonurus cardiaca, and Aloe barbadensis be effective. Herbal drugs cause comparatively fewer side effects. It is believed that the drugs derived from the plants are very safe and produce significant effects in the treatment of various diseases. Today, traditional medicine is being widely used and plants are still considered a major source of natural antioxidants that can serve as a clue for the development of new drugs.

Abstract #1070: Hashimoto`S Encephalopathy with Increased Thyroid Function: About a Case

Abstract #1070: Hashimoto`S Encephalopathy with Increased Thyroid Function: About a Case

L-Arginine Derivatives Are Associated with the Hyperthyroid State in the General Population.

Arginine (ARG) derivatives and thyroid function independently influence atherosclerotic processes. Since thyroid hormones may mediate the association between ARG derivatives and atherosclerosis, this study investigated whether asymmetric and symmetric dimethylarginines (ADMA and SDMA, respectively) as well as homoarginine (hARG) are associated with parameters of thyroid function in the general population. Cross-sectional data from 3689 individuals aged 20-81 years from the population-based Study of Health in Pomerania (SHIP-0) were analyzed. Thyroid function was defined according to serum concentrations of thyrotropin (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). Low and high serum TSH were defined by the cutoffs 0.3 mIU/L and 3 mIU/L, respectively. Serum concentrations of ARG, ADMA, SDMA, and hARG were measured using liquid chromatography-tandem mass spectrometry. ARG, ADMA, SDMA, and hARG were associated with serum concentrations of TSH, fT3, and fT4 by median regression and with categorized TSH values by multinomial logistic regression adjusted for age, sex, smoking status, physical activity, body mass index, and estimated glomerular filtration rate. Levels of ADMA (relative risk [RR] = 5.40 [confidence interval (CI) 1.96-14.86]) and SDMA (RR = 3.55 [CI 1.01-12.70]) were associated with low TSH. In addition, ADMA (β = 0.38 [CI 0.23-0.45]) was positively associated with fT3, while both ADMA (β = 0.98 [CI 0.43-1.54]) and SDMA (β = 1.19 [CI 0.50-1.88]) were positively associated with fT4. No consistent associations of ARG and hARG with thyroid function were detected. The positive associations of ADMA and SDMA with low TSH, fT3, and fT4 argue for a relationship of arginine derivatives with increased thyroid function. This suggests that the atherogenic properties of ADMA and SDMA may be partially mediated by thyroid function.

Factitious thyrotoxicosis caused by dietary supplements and herbals

Overvaluation of the image leads to excessive consumption of dietary supplements and natural products such as multivitamins, herbs and substances used for weight loss. This consumption can lead to changes in the body, among them factitious Thyrotoxicosis. Objective: The goal is to describe what has been published in the scientific community concerning the effects of dietary supplements on the development of exogenous thyrotoxicosis, as well as the consequences for the organism. Methodology: Review of the literature non systematically based on databases Pubmed, Lilacs and Cochrane databases, where 136, 109 and 4 articles were respectively found. Among them 14 were selected according to the criteria of inclusion and exclusion. Development: Laboratory analysis concluded that many supplements contained excess of iodine or thyroid hormone. Most of the times, these substances were not included on product labels, making it difficult ANVISA and FDA inspections. The supplements that were analyzed contained extracts of gingko biloba, kelp, guggulu, xanthohumol and withamina somnifera related to increased thyroid function. The use of these products can lead to the development of factitious thyrotoxicosis that causes tachycardia, irritability, insomnia, cardiovascular disorders and hypertension. Drug interactions and nephrotoxic, hematologic and cardiac effects are also reported with the indiscriminate use of these substances. Conclusion: Literature shows that the use of supplements can cause damage in the body, such as factitious thyrotoxicosis and other systemic effects. However, further studies are needed comparing the relation of food supplementation and thyrotoxicosis as well as an efficient control.

Accurately localizing the thyroid tissue in mature cystic teratoma of ovary by single-photon emission computerized tomography/computerized tomography.

A 30-year-old woman with hyperthyroidism was admitted to hospital. Although increased thyroid function was found, the gland was normal in ultrasonography (USG). Additionally, thyroid iodine uptake and Tc-99m pertechnetate scintigraphy was normal. Abdomen USG detected a cystic pelvic mass in left ovary. A whole-body scan was performed 48 hours after oral ingestion of 29.6 MBq (0.8 mCi) I-131 (iodine-131) revealed a round structure located to the left lower abdomen. Iodine uptake was detected in this cyst which was compatible with functional thyroid tissue demonstrated by SPECT/CT. The patient was underwent surgical operation and histopathology confirmed mature cystic teratoma. Accurate localization and depiction of thyroid tissue in ovary mass was provided with SPECT/CT.

Thyroid antibodies are associated with stenotic lesions in the terminal portion of the internal carotid artery

Several studies have reported moyamoya syndrome associated with thyroid disease, and the mechanism involved in this relationship is unknown. This study aimed to clarify the involvement of thyroid antibodies and thyroid function in intracranial arterial stenosis. The study included 30 patients <65years of age with intracranial arterial steno-occlusion. Patients with definitive moyamoya disease were excluded. Thyroid function and thyroid antibody levels were evaluated. The steno-occlusive site and the presence of moyamoya vessels were evaluated using digital subtraction angiography. The characteristics of intracranial arterial lesions were compared between patients with and without elevated thyroid antibody levels, and between patients with increased thyroid function and those with normal thyroid function. Five patients had increased thyroid function and seven had elevated thyroid antibody levels. Four were diagnosed with Graves' disease, 13 with atherosclerotic intracranial stenosis, two with intracranial arterial dissection, one with vasculitis syndrome and 10 with intracranial stenosis of unknown cause. All patients with Graves' disease and patients with elevated antithyroid peroxidase antibody levels had steno-occlusion in the terminal portion of the internal carotid arteries, whereas most of the patients with normal thyroid function or without elevated thyroid antibody levels had stenosis in the middle cerebral arteries. In young and middle-aged patients, a lesion in the terminal portion of the internal carotid artery was associated with elevated thyroid antibody levels and increased thyroid function. Stenoses found in the terminal portion of the internal carotid artery and immune-mediated thyroid diseases may share a common background.

Effects of a Multivitamin/multimineral Supplement on Young Males with Physical Overtraining: A Placebo-controlled, Randomized, Double-blinded Cross-over Trial

ObjectiveTo investigate the effects of vitamin-mineral supplement on young males with physical overtraining. MethodsTwo hundred and forty male Chinese field artillery personnel who undertook large scale and endurance military training and were on ordinary Chinese diet were randomized to receive a multivitamin/multimineral supplement or a placebo for 1 week. After a 1-week wash-out period, a cross-over with 1 week course of a placebo or multivitamin/multimineral supplement was conducted. Blood and urine samples were analyzed for adrenal, gonadal and thyroid hormones. In addition, cellular immune parameters (CD3+, CD3+CD4+, CD3+CD8+, CD4/CD8, CD3-CD56+, CD3-CD19+) were examined and psychological tests were performed before and after the training program and nutrition intervention. ResultsAfter a large scale and endurance military training, the participants showed significantly increased thyroid function, decreased adrenal cortex, testosterone and immunological function, and significantly increased somatization, anger and tension. Compared to placebo, multivitamin/multimineral intervention showed significant effects on functional recovery of the pituitary – adrenal axis, pituitary-gonadal axis, pituitary- thyroid axis and immune system as well as psychological parameters. ConclusionHigh-intensity military operations have significant impacts on the psychology, physical ability and neuroendocrine-immune system in young males. Appropriate supplementation of multivitamin/multimineral can facilitate the recovery of the psychology, physical ability and neuroendocrine-immune system in young males who take ordinary Chinese diet.

Urinary Bisphenol A Concentration and Thyroid Function in Chinese Adults

Bisphenol A (BPA) is an endocrine disruptor that in animal studies can bind to the thyroid hormone receptor and affect thyroid function. Relevant epidemiologic studies are limited and results are inconsistent. We explored the relationship between urinary BPA and thyroid function in a Chinese population. The study population included 3394 subjects age 40 years or older who were enrolled in a population-based study from Songnan Community, Baoshan District, Shanghai, China, from June through August 2009. We analyzed the association between urinary BPA and thyroid function using multivariate linear regression. Participants were further divided according to thyroid function status, and logistic regression was applied to determine the relationship between urinary BPA and thyroid function. Each one-quartile increase in BPA was related to an increase of 0.068 pmol/l (95% confidence interval = 0.065- 0.071) in free triiodothyronine and a 0.084 μIU/ml decline (-0.099 to -0.069) in thyroid-stimulating hormone (TSH) in men. For women, there was a 0.10 pmol/l (0.09 to 0.11) increase in free triiodothyronine and a 0.13 μIU/ml decline (-0.14 to -0.11) in TSH. High urinary BPA level was associated with increased thyroid function (adjusted odds ratio= 1.71 [1.26 to 2.32]). Our results support previous reports of associations between BPA exposure and altered thyroid hormones in animal models and epidemiologic studies. Because our study is cross-sectional, no causal relationships can be established.

The development of nuclear medicine in Slovenia and Ljubljana; half a century of nuclear medicine in Slovenia

BackgroundNuclear medicine began to be developed in the USA after 1938 when radionuclides were introduced into medicine and in Europe after radionuclides began to be produced at the Harwell reactor (England, 1947). Slovenia began its first investigations in the 1950s. This article describes the development of nuclear medicine in Slovenia and Ljubljana. The first nuclear medicine interventions were performed in Slovenia at the Internal Clinic in Ljubljana in the period 1954–1959. In 1954, Dr Jože Satler started using radioactive iodine for thyroid investigations. In the same year, Dr Bojan Varl, who is considered the pioneer of nuclear medicine in Slovenia, began systematically introducing nuclear medicine. The first radioisotope laboratories were established in January 1960 at the Institute of Oncology and at the Internal Clinic. Under the direction of Dr. Varl, the laboratory at the Internal Clinic developed gradually and in 1973 became the Clinic for Nuclear Medicine with departments for in vivo and in vitro diagnostics and for the treatment of inpatients and outpatients at the thyroid department. The Clinic for Nuclear Medicine became a teaching unit of the Medical Faculty and developed its own post-graduate programme – the first student enrolled in 1972. In the 1960s, radioisotope laboratories opened in the general hospitals of Slovenj Gradec and Celje, and in the 1970s also in Maribor, Izola and Šempeter pri Novi Gorici.ConclusionsNowadays, nuclear medicine units are modernly equipped and the staff is trained in morphological, functional and laboratory diagnostics in clinical medicine. They also work on the treatment of cancer, increased thyroid function and other diseases.

Association between thyroid hormone levels, the number of circulating osteoprogenitor cells, and bone mineral density in euthyroid postmenopausal women

In postmenopausal women, an association between reduced bone mineral density (BMD) and increased number of circulating osteoprogenitor cells (COPs) has been found. Although an increased thyroid function is associated with BMD, thyroid hormones stimulate osteoblast function in vitro. We investigated whether thyroid hormones within the reference range were correlated with the number of COPs and stimulate mineralization in vitro. The number of COPs, defined as CD34+/alkaline phosphatase (AP)+ or CD34+/osteocalcin (OCN)+ cells, was quantified by fluorescence-activated cell sorting (FACS) analysis in 150 euthyroid postmenopausal women. Participants underwent measurement of serum free thyroxine (FT4), thyroid-stimulating hormone levels, and femur BMD. CD34+ cells were isolated from healthy volunteers irrespective of AP or OCN expression, and the effect of triiodothyronine (0.5-10 pmol/L)) on their ability to form mineralized nodules in vitro was studied. The number of COPs was highest among women with high-normal FT4 levels (>1.09 ng/dL). The FT4 levels were correlated positively with circulating log-CD34+/AP+ (r = 0.32, P < .001) and log-CD34/OCN+ cells (r = 0.36, P < .001) and inversely with total femur BMD (r = −0.17, P = .036) but not with femoral neck BMD. In a multivariate analysis, the FT4 levels were positively correlated with the number of COPs, independent of age and BMD. The ability of CD34+ cells to form mineralized nodules increased after exposure from low up to high-normal triiodothyronine concentrations (P for trend = .003). Among euthyroid postmenopausal women, high-normal FT4 levels are correlated with an increased number of circulating immature osteoprogenitor cells and a very mild BMD reduction. Exposure of CD34+ cells to physiological triiodothyronine concentrations stimulates mineralization in vitro.

Increased Thyroid Function and Elevated Thyroid Autoantibodies in Pediatric Patients With Moyamoya Disease

The purpose of this study was to investigate whether thyroid function and thyroid autoantibodies were associated with the risk of moyamoya disease in pediatric subjects. Thyroid function and thyroid autoantibodies were evaluated in patients with moyamoya disease and control subjects, and their associations with moyamoya disease were estimated using multivariate analysis. We included 114 pediatric patients and 114 healthy control subjects. The patients displayed higher prevalence of increased thyroid function and elevated thyroid autoantibodies in comparison with control subjects. These remained significant after multivariate adjustment; the ORs (95% CI) for increased thyroid function and evaluated thyroid autoantibodies were evaluated as 12.47 (1.55 to 100.51) and 4.33 (1.29 to 14.59), respectively. Increased thyroid function and elevated thyroid autoantibodies are associated with moyamoya disease and therefore monitoring of thyroid function and thyroid autoantibodies in patients with moyamoya disease is suggested, which might help to guide subsequent clinical management.

Thyrocyte-specific Gq/G11 deficiency impairs thyroid function and prevents goiter development

The function of the adult thyroid is regulated by thyroid-stimulating hormone (TSH), which acts through a G protein-coupled receptor. Overactivation of the TSH receptor results in hyperthyroidism and goiter. The Gs-mediated stimulation of adenylyl cyclase-dependent cAMP formation has been regarded as the principal intracellular signaling mechanism mediating the action of TSH. Here we show that the Gq/G11-mediated signaling pathway plays an unexpected and essential role in the regulation of thyroid function. Mice lacking the alpha subunits of Gq and G11 specifically in thyroid epithelial cells showed severely reduced iodine organification and thyroid hormone secretion in response to TSH, and many developed hypothyroidism within months after birth. In addition, thyrocyte-specific Galphaq/Galpha11-deficient mice lacked the normal proliferative thyroid response to TSH or goitrogenic diet, indicating an essential role of this pathway in the adaptive growth of the thyroid gland. Our data suggest that Gq/G11 and their downstream effectors are promising targets to interfere with increased thyroid function and growth.

Prevalence of Thyroid Dysfunction in Thai HIV-Infected Patients

Increasing prevalence of thyroid function abnormality has been reported in HIV-infected patients. We aim to evaluate the prevalence and assess risk factors of thyroid dysfunction in Thai HIV-infected patients. A cross-sectional study was conducted. Serum thyroid hormone concentrations (FT4, FT3, and TSH) and thyroid autoantibodies (TgAb and TPOAb) were measured by electrochemiluminescence immunoassay. A total of 200 HIV-infected outpatients were included. Ninety-seven patients (48.5%) were men (mean age of 36.3 +/- 8.3 years). Duration of HIV infection was 49.6 +/- 35.1 months and 53% had previous opportunistic infections (OI). Mean CD4 cell count was 340.6 +/- 173.1 cells/mm(3). Of these, 167 patients (83.5%) received antiretroviral therapy (ARV). Abnormal thyroid function test was detected in 32 patients (16%). Twenty-seven patients (13.5%) had decreased thyroid function (primary hypothyroidism 3, subclinical hypothyroidism 12, and low FT4 with low or normal TSH 12) whereas 5 patients had increased thyroid function (overt hyperthyroidism 1, subclinical hyperthyroidism 1, and isolated high FT3 3). None had clinical features of thyroid hormone dysfunction. Thirteen patients (6.5%) had thyroid antibody positive. Patients who received ARV had higher mean FT3 levels than those who were naïve to ARV (p = 0.017). History of previous OI was found to be an independently significant risk factor for decreased thyroid function with the odds ratio of 3.28 (95% CI =1.183-9.099; p = 0.022). Hypothyroidism was common among Thai HIV-infected patients, especially in those who had history of previous OI. It is therefore suggested that screening and/or monitoring of thyroid hormone in HIV-infected patients should be considered.